Maine (AP) The federal government says it’s considering the concerns of a lobster fishermen’s group about a plan to try to save an endangered species of whale.

The plan concerns the North Atlantic right whale, which numbers only about 400. The Maine Lobstermen’s Association pulled its support from the plan this summer because of concerns it placed too much onus on lobstermen, who would be called to remove miles of trap rope from the water.

The lobstermen’s group’s concerns included that right whales are also subject to entanglement in fishing gear in Canadian waters. Chris Oliver, assistant administrator for the National Marine Fisheries Service, released a letter Wednesday that said the U.S. is working with Canada to reduce that problem.

He also stated that “monitoring and research alone” won’t save the whales.